In this paper we study a numerical method for the simulation of free surface flows of viscoplastic (Herschel-Bulkley) fluids. The approach is based on the level set method for capturing the free surface evolution and on locally refined and dynamically adapted octree cartesian staggered grids for the discretization of fluid and level set equations. A regularized model is applied to handle the no...

We study the fingering instability that occurs at the contact line of a thin sheet of a yield-stress fluid flowing down an incline. We derive an expression for the wavelength of the finger pattern as a function of inclination angle for a Herschel-Bulkley fluid. The wavelength is predicted to diverge at a finite angle which is related to the yield stress of the fluid. We also measure the wavelen...

The present paper sheds some light on investigating the effect of pulsatility on flow through a tapered artery. Blood has been represented by a nonNewtonian fluid obeying Herschel-Bulkley equation. Using the Reynolds number as the perturbation parameter, a perturbation technique is adopted to solve the resulting quasi-steady non-linear coupled implicit system of differential equations. Analytic...

The flow curves, viz. the curves of stationary stress under steady shearing, are obtained close to the glass transition in dense colloidal dispersions using asymptotic expansions in the schematic F₁₂(γ)-model of mode coupling theory. The shear thinning of the viscosity in fluid states and the yielding of glassy states is discussed. At the transition between fluid and shear-molten glass, simple ...

This work addresses the numerical computation of the two-dimensional flow of yield stress fluids (with Bingham and Herschel-Bulkley models) based on a variational approach and a finite element discretization. The main goal of this paper is to propose an alternative optimization method to existing procedures such as penalization and augmented Lagrangian techniques. It is shown that the minimum p...